Comparison of acoustic travel-time measurements of solar meridional circulation from SDO/HMI and SOHO/MDIZhi-Chao Liang, Aaron C. Birch, Thomas L. Duvall, Laurent Gizon and Jesper SchouA&A, 601 (2017) A46DOI: https://doi.org/10.1051/0004-6361/201730416
